1. Field of the Invention
The present invention relates to an electrical socket, and more particularly to an electrical socket having an improved cam to prolong a path which an electronic package moved in the electrical socket.
2. Description of Related Art
U.S. Pat. No. 6,250,941 issued to Huang et al. on Jun. 26, 2001 discloses a Zero Insertion Force (ZIF) socket for use with a Pin Grid Array (PGA) electronic package. The socket includes a base, a cover mounted upon the base, and a cam assembled between the base and the cover. The cam includes an upper portion and a lower portion. The upper portion is composed of an upper disk and a lower disk coaxial with the upper disk. The upper disk has a lateral protrusion protruding from a lateral side thereof. The lower portion is formed under the upper portion and parallel to but offset from the axis of the upper portion. The lower disk and the lower portion have a common tangent plane. The tangent plane is located on the lower portion offset direction. The offset direction and the lateral protrusion have a right angle.
When the electronic package mounted upon the cover, the cam is rotated to drive the cover moving along the base between an open position and a closed position. FIG. 1 shows a relative position between a pin and a contact of the ZIF socket. When the ZIF socket is positioned at the closed position, the pin 2′ engages with a mating portion 1′ of the contact and located at an end position. When the cam is rotated 180 degree to the open position, the pin 2′ drops out the mating portion 1′ of contact and returned to an original position. The pin moves along a unilateral path from the closed position to the open position or from the open position to the closed position as arrows shown in FIG. 1.
The ZIF socket may cause the customs complaints for the pins not good engaging with the contacts and dropout the contacts, that's caused by many reasons, such as the contacts having big holding force.
Therefore, an improved electrical socket is needed.